ADU Rules in San Diego, California

Complete guide to building an Accessory Dwelling Unit in San Diego — zoning, setbacks, permits, costs, and more.

Max Size: 1,200 sq ft Setbacks: 4 ft Parking: Varies Verified: 2026-07-20
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San Diego remains one of America's highest-volume ADU markets — 5,720 ADUs were permitted from 2021 to 2024 — but its famous ADU Bonus Program was sharply scaled back in 2025. After a 5-4 council vote in June 2025 and final passage in late July 2025 (Ordinance O-21989, effective August 2025 outside the Coastal Zone; Coastal Zone application still awaits California Coastal Commission certification — confirm status with DSD), bonus ADUs on single-family lots are now capped at 4 units on lots of 8,000 sq ft or less, 5 on lots of 8,001-10,000 sq ft, and 6 on lots over 10,000 sq ft, and the program was eliminated in the eight lowest-density RS-1 zones except in High/Highest Resource Areas. The standard entitlement is untouched: every single-family lot still gets 1 detached ADU (up to 1,200 sq ft), 1 conversion ADU, and 1 JADU (up to 500 sq ft) with 4-ft side/rear setbacks and no parking outside the Coastal Overlay Zone. New costs apply — a Community Enhancement Fee for bonus/affordable ADUs under 750 sq ft, the General Plan Maintenance Fee on all ADUs, and 1 parking space per bonus/affordable ADU outside Transit Priority Areas — while AB 1033 condo sales of ADUs are now expressly allowed. The state HCD warned in June 2025 that parts of the rollback may conflict with state law, so verify current program details with Development Services before designing a multi-ADU project.

Zoning & Size Requirements [1][2][3]

Yes — San Diego allows ADUs. A detached ADU can typically be up to 1,200 sq ft under current California and San Diego zoning rules.

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Allowed ZonesAll residential zones; also allowed in some commercial mixed-use zones
Max Size (Detached)1,200 sq ft
Max Size (Attached)1,200 sq ft or 50% of primary dwelling
Max Size (JADU)500 sq ft
Max Height2 stories, with height set by the underlying base/overlay zone (state floor 16-18 ft) — no flat citywide 25 ft cap
Max UnitsBase: 1 ADU + 1 JADU per single-family lot. ADU Bonus Program (reformed Aug 2025) caps total ADUs by lot size everywhere — 4 at 8,000 sq ft or less, 5 for 8,001-10,000 sq ft, 6 at 10,000 sq ft or more; bonus market-rate ADUs require a deed-restricted affordable ADU, and the program was eliminated in eight low-density RS zones (except High/Highest Resource Areas). Multifamily: up to 8 detached ADUs (SB 1211, capped at the number of existing units).

Setback Requirements [1][2][3]

San Diego requires a rear setback of about 4 ft for a detached ADU, and parking requirements vary by unit size or location. Owner-occupancy is not required — you can rent it out without living on the property.

Rear Setback4 ft
Side Setback4 ft
Front SetbackPer underlying zone
Parking RequiredNo parking required, except 1 off-street space in the Coastal Overlay Beach Impact Area outside a Transit Priority Area (standard ADU exemptions apply)
Owner OccupancyNot required
Min Lot SizeNo minimum lot size for JADUs

Permit Process & Fees [4]

An ADU permit in San Diego typically costs $3,500-$12,000 and takes 60 days (often faster), through a ministerial, by-right review.

Approval ProcessMinisterial review; no discretionary approval needed
Review Timeline60 days (often faster)
Permit Fees$3,500-$12,000
Impact FeesWaived for units under 750 sq ft
Plan CheckStandard plan check included
Pre-Approved PlansYes — companion unit program with pre-approved designs

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Construction Costs [5][6]

Building an ADU in San Diego typically costs $120,000-$300,000 ($180-$350 per sq ft); a garage conversion runs $70,000-$160,000.

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Average Build Cost$120,000-$300,000
Cost per Sq Ft$180-$350
Garage Conversion$70,000-$160,000
Prefab ADU (Installed)$90,000-$220,000

Finance Your ADU Project

Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders.

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Rental Income Potential [7][8]

A 2-bedroom ADU in San Diego rents for around $2,000-$2,800/mo, an estimated 7-11% annual return.

Avg Rent (1 Bedroom)$1,600-$2,200/mo
Avg Rent (2 Bedroom)$2,000-$2,800/mo
Short-Term RentalNot allowed for ADUs — minimum 31-consecutive-day lease (Information Bulletin 400); JADUs are barred from short-term rental
Est. Annual ROI7-11% annual return

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Recent Law Changes

What's Changed Recently

  • June 13, 2025 — California HCD sent San Diego a warning letter that the proposed ADU Bonus Program rollback could violate state housing law and jeopardize the city's Prohousing designation, demanding a response by July 11, 2025.
  • June 16-17, 2025 — City Council voted 5-4 to cap bonus ADUs by lot size: 4 units on lots ≤8,000 sq ft, 5 on lots 8,001-10,000 sq ft, 6 on lots over 10,000 sq ft (the program had produced 875 of 5,720 ADUs permitted 2021-2024).
  • Late July 2025 — Council gave final passage to the ~25-reform package; amendments took effect approximately August 22, 2025 outside the Coastal Zone (Ordinance O-21989 per IB-400); Coastal Zone effectiveness awaits Coastal Commission certification — confirm timing with DSD.
  • August 2025 — Bonus program eliminated in RS-1-1 through RS-1-4 and RS-1-8 through RS-1-11 zones except High/Highest Resource Areas; 1 off-street parking space required per bonus/affordable ADU outside Transit Priority Areas; 4-ft setbacks and two-evacuation-route requirements added in High/Very High Fire Hazard Severity Zones.
  • 2025 — AB 1033 implemented: ADUs may be subdivided and sold as condominiums separately from the primary home, except units with San Diego Housing Commission assistance or active rent restrictions.
  • January 1, 2026 — Statewide: SB 543 deems ADU applications approved if the city misses the 60-day review clock; AB 1154 limits JADU owner-occupancy requirements to units sharing a bathroom with the main house.

Tips for Building an ADU in San Diego

  • The rollback only hit the Bonus Program — the standard package (1 detached ADU up to 1,200 sq ft + 1 conversion ADU + 1 JADU on a single-family lot) is unchanged and still ministerial.
  • If your lot is zoned RS-1-1 through RS-1-11, check the CTCAC/HCD Opportunity Area map before planning bonus units — the Bonus Program now applies there only in High or Highest Resource Areas.
  • Budget for fees even on small units: the General Plan Maintenance Fee applies to all ADUs/JADUs, ADUs are not exempt from development impact or inclusionary fees, and bonus/affordable ADUs under 750 sq ft now pay a Community Enhancement Fee — get a written fee estimate from DSD before finalizing plans.
  • Outside a Transit Priority Area, plan 1 on-site parking space per bonus or affordable ADU; standard ADUs still need no parking outside the Coastal Overlay Zone's Beach Impact Area.
  • You can shortcut design costs with permit-ready plans — San Diego accepts County of San Diego PRADU and City of Encinitas pre-approved plans if they meet city submittal guidelines.
  • ADUs cannot be rented for under 31 consecutive days and JADUs are barred from short-term occupancy entirely — underwrite on long-term rents; if you want an exit option, AB 1033 now lets you sell a qualifying ADU as a condo.

ADU Builders in San Diego

Looking for an ADU builder in San Diego? ADU projects need a contractor experienced with local zoning, the permit process, and utility connections — not every general contractor has built one. We match San Diego homeowners with experienced local ADU contractors who provide free, no-obligation quotes. Getting at least three bids typically saves 20-40% on the same scope.

Sources & References

All data on this page is sourced from official government records and verified market data. View our full methodology.

  1. Information Bulletin 400: Accessory Dwelling Unit / Junior Accessory Dwelling Unit (City of San Diego DSD) municipal — Accessed 2026-07-20
  2. City Council Adopts Reforms to Accessory Dwelling Unit Program (Inside San Diego, official city news) municipal — Accessed 2026-07-20
  3. San Diego City Council approves rollback of ADU incentives (KPBS, June 17, 2025) News Source — Accessed 2026-07-20
  4. Information Bulletin 400: ADU/JADU Building Permit requirements (City of San Diego DSD) municipal — Accessed 2026-07-20
  5. Angi — ADU Construction Cost Data Market Data — Accessed 2026-02-24
  6. Angi — Local ADU Contractor Costs Market Data — Accessed 2026-02-24
  7. Zillow Rental Manager — Market Rent Data Market Data — Accessed 2026-02-24
  8. HUD Fair Market Rents Government Data — Accessed 2026-02-24
  9. California ADU Handbook — HCD Government Data — Accessed 2026-02-24
  10. California HCD — Accessory Dwelling Unit Handbook (updated March 2026) Government Data — Accessed 2026-06-28
  11. CA SB 543 (2025-2026) — Accessory dwelling units and junior accessory dwelling units (full bill text) Government Data — Accessed 2026-06-28

Frequently Asked Questions

Can I build an ADU in San Diego?

Yes. ADUs are allowed in All residential zones; also allowed in some commercial mixed-use zones in San Diego. The maximum size for a detached ADU is 1,200 sq ft. Owner-occupancy is not required, so you can rent out the ADU.

How much does an ADU cost in San Diego?

ADU construction in San Diego typically costs $120,000-$300,000. Garage conversions run $70,000-$160,000, and prefab ADUs cost $90,000-$220,000.

How much can I rent an ADU for in San Diego?

Average ADU rents in San Diego are $1,600-$2,200/mo for a 1-bedroom and $2,000-$2,800/mo for a 2-bedroom unit.

Do I need parking for an ADU in San Diego?

No parking required, except 1 off-street space in the Coastal Overlay Beach Impact Area outside a Transit Priority Area (standard ADU exemptions apply). Check with San Diego planning department for the latest California ADU parking rules, as many states have relaxed requirements in recent years.

How long does it take to get an ADU permit in San Diego?

The permit review timeline in San Diego is 60 days (often faster). Fees range from $3,500-$12,000.

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About this information: This page is an informational summary of publicly available regulations - it is not legal, financial, or professional advice, and it is not a substitute for confirming requirements with your local planning department. Rules change frequently; always verify current requirements before designing, budgeting, or building. Last verified: 2026-07-20. Contractors we introduce are independent businesses - verify license and insurance directly before hiring. Spotted an error? Tell us - we verify against primary sources and correct quickly.

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